Search Images Maps Play YouTube News Gmail Drive More »
Sign in
Screen reader users: click this link for accessible mode. Accessible mode has the same essential features but works better with your reader.

Patents

  1. Advanced Patent Search
Publication numberUS8138511 B2
Publication typeGrant
Application numberUS 11/567,977
Publication dateMar 20, 2012
Filing dateDec 7, 2006
Priority dateMar 9, 2001
Also published asDE10111501A1, US7169632, US20040046179, US20080179380, WO2002073705A2, WO2002073705A3, WO2002073705A8
Publication number11567977, 567977, US 8138511 B2, US 8138511B2, US-B2-8138511, US8138511 B2, US8138511B2
InventorsJohannes Baur, Dominik Eisert, Michael Fehrer, Berthold Hahn, Volker Härle, Marianne Ortmann, Uwe Strauss, Johannes Völkl, Ulrich Zehnder
Original AssigneeOsram Ag
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Radiation-emitting semiconductor component and method for producing the semiconductor component
US 8138511 B2
Abstract
A radiation-emitting semiconductor component has an improved radiation efficiency. The semiconductor component has a multilayer structure with an active layer for generating radiation within the multilayer structure and also a window having a first and a second main surface. The multi-layer structure adjoins the first main surface of the window. At least one recess, such as a trench or a pit, is formed in the window from the second main surface for the purpose of increasing the radiation efficiency. The recess preferably has a trapezoidal cross section tapering toward the first main surface and can be produced for example by sawing into the window.
Images(6)
Previous page
Next page
Claims(31)
What is claimed is:
1. A radiation-emitting semiconductor component, comprising:
a multilayer structure including an active layer for generating radiation in said multilayer structure;
electrical contacts connected to said active layer; and
a radiation-transmissive window with a first main surface adjoining said multilayer structure and a second main surface opposite said first main surface, wherein said window contains a material selected from the group consisting of ITO, SnO, ZnO, and InO; and
said second main surface having at least one void selected from the group consisting of a trench recess and a pit recess formed therein for increasing a coupling-out of radiation from said window;
wherein at least part of the radiation generated in the radiation-emitting semiconductor component is transmitted through a side surface of the void.
2. The semiconductor component according to claim 1, wherein said window is formed with side surfaces perpendicular to said first and second main surfaces.
3. The semiconductor component according to claim 1, wherein said window is formed with side surfaces having partial regions orthogonal to said first and second main surfaces.
4. The semiconductor component according to claim 1, wherein said window has an enveloping cuboid basic shape.
5. The semiconductor component according to claim 1, wherein said void has at least one planar side surface enclosing an angle between 20° and 70° with said second main surface.
6. The semiconductor component according to claim 1, wherein said void has a bottom surface substantially parallel to said second main surface.
7. The semiconductor component according to claim 1, wherein said void is a trench recess formed with a triangular or trapezoidal cross section tapering toward said first main surface.
8. The semiconductor component according to claim 1, wherein said at least one void is one of a plurality of trench recesses formed in said window.
9. The semiconductor component according to claim 8, wherein
at least two trench recesses of said plurality of trench recesses cross one another.
10. The semiconductor component according to claim 1, wherein said void is bounded by at least one curved surface.
11. The semiconductor component according to claim 10, wherein said void has a form substantially describing a hemisphere, a sphere segment, an ellipsoid segment, a cone, or a truncated cone.
12. The semiconductor component according to claim 1, wherein said window has a refractive index greater than a refractive index of said multilayer structure.
13. The semiconductor component according to claim 1, wherein said multilayer structure is based on GaN.
14. The semiconductor component according to claim 13, wherein said multilayer structure contains at least one gallium compound selected from the group consisting of GaN, Al1-xGaxN (0□x□1), In1-xGaxN (0□x□1), and Al1-x-yInxGayN (0□x□1), (0□y□1).
15. The semiconductor component according to claim 1 wherein said multilayer structure is an epitaxy product.
16. The semiconductor component according to claim 15, wherein said multilayer structure is deposited on an epitaxial substrate and said window is produced from said epitaxial substrate.
17. The semiconductor component according to claim 15, wherein said multilayer structure is deposited on an epitaxial substrate and said epitaxial substrate is stripped away after the epitaxy.
18. The semiconductor component according to claim 1, wherein said window is connected to said multilayer structure by a wafer bonding process.
19. The semiconductor component according to claim 1, wherein the semiconductor component is arranged on a heat sink.
20. The semiconductor component according to claim 19, wherein said heat sink is a metal heat sink.
21. The semiconductor component according to claim 1, wherein the semiconductor component is part of an optical component, said optical component being capable of radiating polychromatic light.
22. The semiconductor component according to claim 21, wherein the semiconductor component is covered with a potting, said potting serving as a carrier or as a matrix for a radiation conversion element, the polychromatic light radiated by the optical component comprising light of the semiconductor component and light converted by the radiation conversion element.
23. An optical component comprising:
an angled heat sink and
at least two semiconductor components according to claim 1,
wherein the at least two semiconductor components are applied to at least two different surfaces of said angled heat sink.
24. A method for producing a semiconductor component, the method comprising:
providing a window layer having a first main surface and a second main surface opposite the first main surface;
applying a semiconductor layer sequence to the first main surface of the window layer;
forming at least one recess in the window layer from the second main surface; and
completing the semiconductor component according to claim 1.
25. The method according to claim 24, which comprises forming the recess by sawing into the window layer on the second main surface.
26. The method according to claim 25, which comprises sawing with a saw blade having a shaping edge.
27. The method according to claim 26, which comprises sawing with a saw blade having a trapezoidal cross section in a sawing region.
28. The method according to claim 24, which comprises etching the recess into the second main surface.
29. The method according to claim 24, which comprises forming the recess with a laser ablation process.
30. The semiconductor component according to claim 1, wherein said window contains ITO.
31. The semiconductor component according to claim 3, wherein radiation generated by the active layer is primarily emerges from the window through side surfaces of the window, side surfaces of the void, and the second main surface of the window.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application and claims priority to U.S. Application Ser. No. 10/657,841, filed Sep. 9, 2003 now U.S. Pat. No. 7,169,632, which is a continuation application of International Application No. PCT/DE02/00514, filed Feb. 13, 2002, which claims priority to German Application Serial No. 10111501.6, filed on Mar. 9, 2001, the contents of which are incorporated by reference herein in their entirety.

BACKGROUND OF THE INVENTION Field of the Invention

The invention lies in the field of semiconductor technology. More specifically, the invention relates to a radiation-emitting semiconductor component having a multilayer structure, an active layer serving for generating radiation within the multilayer structure, electrical contacts, which are electrically conductively connected to the active layer, and a radiation-transmissive window having a first main surface and a second main surface opposite to the first main surface. The first main surface of the window adjoins the multilayer structure. The invention also pertains to a method of producing such a radiation-emitting semiconductor component.

Radiation-emitting semiconductor components of the type mentioned generally have a semiconductor multilayer system with an active layer serving for generating radiation, which system is applied to a carrier. Radiation is coupled out through the carrier, the carrier being transparent with respect to the radiation thus generated. In that configuration, however, the radiation efficiency is greatly limited by total reflection at the carrier surface. This problem surface is particularly pronounced in the case of carriers having a high refractive index, such as SiC (silicon carbide) substrates for example, and it is further aggravated if the refractive index of the carrier is greater than the refractive, index of the multilayer system.

The influence of total reflection on the coupling-out of radiation is illustrated by way of an example in FIG. 9 using a prior art GaN-based multilayer system 20 on a parallelepipedal SiC substrate 19 that it rectangular in section. The SiC substrate 19 has a refractive index of about 2.7 and it represents the optically denser medium by comparison with the multilayer system 20, which has a refractive index of about 2.5. The semiconductor structure shown is surrounded by a medium having a low refractive index, for example air.

The multilayer structure 20 has an active radiation-generating layer 21. A small radiation-emitting volume 23, which can be described in an approximation as an isotropic point radiator, shall be picked out of the active layer 21. The following consideration is applicable to virtually all such partial volumes 21 of the active layer.

The radiation 22 emitted by the volume 23 in the direction of the SiC substrate 19 firstly impinges on the multilayer system/substrate interface and, upon entering the substrate is refracted in the direction of the normal to the interface.

Direct coupling-out of the radiation at the substrate main surface 25 opposite to the interface is possible only for radiation portions whose angle of incidence is less than the angle of total reflection (in each case relative to the normal to the coupling-out surface 25). For a substrate of high refractive index, the angle of total reflection is comparatively small and amounts to about 22° for SiC, for example.

Therefore, only a small portion 22 c of the radiation generated is directly coupled out from the center of the beam pencil 22 a, b, c. The remainder of the radiation generated in subjected to total reflection.

The radiation portion 22 b subjected to total reflection at the coupling-out surface 25 subsequently impinges on the substrate side surface 26 at an even shallower angle and is once again subjected to total reflection.

The remaining radiation portions 22 a, which first impinge on the side surfaces 26 of the substrate 19, are likewise subjected to total reflection firstly at the side surfaces 26 and then at the coupling-out surface 25.

In the case of the right-angled (i.e., orthogonal) configuration of side and main surfaces shown f, the angle of incidence undergoes transition after reflection into itself or the complementary angle, so that the radiation portions 22 a, b cannot be coupled out at these our-faces even after multiple reflections.

Consequently, only a very small portion 22 c of the entire radiation 22 emitted in the direction of the substrate 19 is coupled out. The remainder of the radiation 22 a, b circulates in the substrate 19 while undergoing multiple total reflection, possibly enters the multilayer structure 20 again and is finally absorbed in the course of this cyclic propagation.

U.S. Pat. No. 6,229,160 and the corresponding German patent application DE 198 07 758 A1 disclose a light-emitting semiconductor component whose semiconductor side surfaces are completely or partly beveled in order to increase the radiation efficiency, so that the substrate acquires the form of a truncated pyramid. This beveling reduces the angle of incidence for parts of the radiation generated upon impingement on the side surfaces at the angle of total reflection, so that these radiation portions can be coupled out.

Since the additional coupling-out of radiation is effected only at the edge regions of the component, the radiation efficiency is increased only slightly, particularly in the case of large-surface components with comparatively thin substrates. Moreover, many placement installations are designed for semiconductor chips with a substrate in parallelepipedal or cuboid form. Changing the basic form of the substrate may lead to functional disturbances or necessitate costly conversions in the case of such installations.

SUMMARY OF THE INVENTION

It is accordingly an object of the invention to provide a radiation-emitting semiconductor component and a corresponding production method which overcome the above-mentioned disadvantages of the heretofore-known devices and methods of this general type and which provide for a radiation-emitting semiconductor component having an improved radiation efficiency.

With the foregoing and other objects in view there is provided, in accordance with the invention, a radiation-emitting semiconductor component, comprising:

a multilayer structure including an active layer for generating radiation in the multilayer structure;

electrical contacts connected to the active layer;

a radiation-transmissive window with a first main surface adjoining the multilayer structure and a second main surface; opposite the first main surface;

the second main surface having at least one void, such as a trench recess or a pit recess, formed therein for increasing a coupling-out of radiation from the window.

In other words, the invention provides for the formation of a radiation-emitting semiconductor component having a multilayer structure, an active layer serving for generating radiation within the multilayer structure, contacts electrically connected to the active layer, and a window which is transmissive for the radiation generated and has a first main surface and a second main surface opposite to the first main surface, the first main surface of the window adjoining the multilayer structure and at least one trench-like or pit-like recess being formed in the window from the second main surface for the purpose of increasing the radiation efficiency.

In this case, the recess is embodied in such way that parts of the radiation generated are coupled out at its boundary surfaces or reflected in a manner that promotes the coupling-out from the window.

A coupling-out of radiation portions is achieved by virtue of the fact that the boundary surfaces of the recess are at least partly arranged in such a way that the angle of incidence of said radiation portions on the boundary surfaces is as small as possible and, in particular, is less than the angle of total reflection.

Reflection promoting the coupling-out is present for example if radiation portions are firstly subjected to total reflection by the boundary surfaces of the recess, the cyclic propagation being broken within the window, so that the relevant radiation portions can be coupled out at least after a few further reflections at a boundary surface of the window.

The interruption of a cyclic propagation has the effect of increasing the radiation efficiency particularly in the case of a window whose side surfaces are arranged perpendicularly to the main surfaces. As described in the introduction, cyclically propagating radiation pencils form very easily in the case of such arrangements with a cubic or parallelepipedal window, with the result that the proportion of radiation that cannot be coupled out is correspondingly high.

Increasing the radiation efficiency by means of a recess in the window advantageously requires no changes to the enveloping basic form of the window, so that production and placement installations whose function is defined for specific predetermined basic forms of the window can also be used for producing components according to the invention. The invention can achieve, in particular, a high radiation efficiency with known and established basic forms of window such as, for example, an enveloping cube or parallelepiped form.

In order to further increase the radiation efficiency, preferably a plurality of recesses are formed in the window in the case of the invention. A plurality of uniform recesses is particularly preferred with regard to the number of production steps, which is to be kept low.

In contrast to edge structuring of the window in order to increase the radiation efficiency, for example by beveling the side surfaces, the invention can achieve an improved coupling-out over a larger surface and a more uniform distribution of the coupled-out radiation on this surface. This is particularly advantageous for large-surface components since, with the component surface scaled upward, the ratio of periphery to surface decreases. Therefore, in the case of large-surface components, means for increasing the radiation efficiency that are restricted to the periphery of the components are generally far less efficient than means for increasing the radiation efficiency that are applied in the surface.

In a preferred refinement of the invention, the recess in the window has at least one planar side surface, which forms an angle that differs from 90.1 with the second main surface of the window. Said angle is particularly preferably between 20° and 70°. Such a recess may be realized for example in the form of a trench with side walls which are inclined with respect to the main surfaces, which trench can be produced for example by correspondingly sawing into the window. Such a trench preferably has a trapezoidal cross section tapering in the direction of the multilayer structure.

In order to further increase the radiation efficiency, it the also possible to form a plurality of trenches that cross one another or run parallel. A parallel arrangement brings about an asymmetrical directional characteristic of the radiation generated, while trenches that cross one another lead to a uniform distribution of the coupled-out radiation. One of the two embodiments may be more advantageous depending on the surface of application.

In a further preferred refinement of the invention, the recess is completely or partly bounded by curved surfaces. In an advantageous manner, reflection at curved boundary surfaces of a recess largely precludes cyclic propagations. In this case, the recesses may be formed in particular in the form of a hemisphere, a sphere segment, an ellipsoid segment, a cone or a truncated cone. Similar forms which emerge for example from the abovementioned basic forms through distortions such as stretching, compression or shearing are also suitable.

Such forms can be produced for example by laser ablation or etching. The abovementioned trench-type recesses may also be bounded by curved surfaces and be formed for example with a semicircular cross section.

In a preferred development of the invention, the multilayer structure is produced by epitaxy. The window may subsequently also be produced from the epitaxial substrate. The invention has particular advantages in the case of substrates of high refractive index such as sic, for example, with correspondingly large total reflection ranges, particularly when the refractive index of the substrate is greater than the refractive index of the multilayer structure. In this case, the refractive index of the multilayer structure is to be understood as the refractive index of that region of the multilayer structure which adjoins the substrate, since the extent of total reflection is significantly determined by the jump in refractive index at the interface between substrate and multilayer structure. The multilayer structure is generally composed of materials which have negligible differences in refractive index with respect to one another compared with the refractive index of the substrate. Therefore, the average refractive index of the materials contained in the multilayer structure can also be used as the refractive index of said multilayer structure.

As described in the introduction, this case arises primarily with GaN-based multilayer structures. These are multilayer structures which contain GaN or a compound that is derived therefrom or related thereto. These include, in particular, GaN itself, mixed-crystal systems based thereon, such as AlGaN (Al1-xGaxN, 0≦x≦1), InGAN (In1-xGaxN, 0≦x≦1) and AlInGaN (Al1-x-yInxGayN, 0≦x≦1, 0≦y≦1) and also AlN, InN and InAlN (In1-xAlxN, 0≦x≦1).

Such multilayer structures are usually grown by epitaxy on an SiC or sapphire substrate which is at least partly transparent to the radiation generated, principally in the blue and green spectral region. In the case of both substrates, the invention can increase the radiation efficiency by reducing the total reflection losses, the invention being particularly advantageous for SiC substrates on account of the problem surface resulting from the high refractive index as described in the introduction.

However, the invention is not restricted to GaN-based systems, but rather may likewise be applied to other semiconductor systems such as, for example, to GaAs- GaP- or ZnSe-based materials. Here, too, a considerable part of the radiation generated remains in the multi-layer structure/window arrangement on account of total reflection and is finally absorbed.

Likewise, the invention is also advantageous for window materials other than those mentioned-hitherto, for example quartz glass, diamond, ITO (indium tin oxide) or materials based on ZnO, SnO, InO or GaP, since it is generally the case with all these windows that, during the coupling-out, there is a transition to an optically leas dense medium at which total reflection can occur and the degree of coupling-out is correspondingly reduced.

Furthermore, the invention is also advantageous for semiconductor bodies or windows that are potted or provided with an encapsulation in some other way, since the encapsulation generally has the lower refractive index, so that the radiation efficiency is reduced by total reflection in this case as well.

A window made of the abovementioned materials may be applied to the multilayer structure after the production of the latter. During the epitaxial production, this is possible for example in that after the epitaxy the epitaxial substrate is stripped away and in place thereof the window is connected to the multilayer structure by means of a wafer bonding method. As an alternative, the window may also be applied to the semiconductor surface produced by epitaxy and afterward the epitaxial substrate may be stripped away. This procedure has the advantage that the epitaxial substrate can be reused, which leads to significant coot advantage particularly in the case of: expensive materials such as SiC substrates, for example.

A method according to the invention for producing a radiation-emitting semiconductor component of the type mentioned begins with the provision of a window layer, for example in the form of a suitable substrate or wafer, having a first main surface and a second main surface opposite to the first main surface.

In the next step, a semiconductor layer sequence corresponding to the multilayer structure to be formed is applied to the first main surface. The application is preferably by epitaxy or by means of a water-bonding method.

Afterward, a saw blade with a shaping edge is used to saw into the window layer from the second main surface and a trench-type recess is thus formed in the substrate. In this case, the cutting depth is less than the thickness of the window layer.

The components are finally completed. This comprises, for is example, contact connection and singulation of the semiconductor layer sequence. During singulation, the composite comprising window layer and semiconductor layer sequence is divided into a plurality of windows each with a multilayer structure arranged thereon.

As an alternative, the recesses can also be etched using a suitable mask technique or produced by means of laser ablation. This alternative makes it possible to form spatially isolated recesses, that is to say recesses which do not extend over the entire surface of the window layer or larger partial regions thereof.

Isolated recesses may be formed as described above, for example, in the shape of a cone, a truncated cone, a hemisphere, a sphere segment, an ellipsoid segment or a similar form.

Other features which are considered as characteristic for the invention are set forth in the appended claims.

Although the invention is illustrated and described herein as embodied in a radiation-emitting semiconductor component and method for producing it, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.

The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a diagrammatic perspective, partly sectional illustration of a first exemplary embodiment of a, semiconductor component according to the invention;

FIG. 1B is a diagrammatic detail view of a portion of the component of FIG. 1A:

FIG. 2 is a diagrammatic perspective illustration of a second exemplary embodiment of a semiconductor component according to the invention;

FIG. 3A is a diagrammatic perspective view of a third exemplary embodiment of a semiconductor component according to the invention;

FIG. 3B in a sectional view thereof;

FIG. 4 is a diagrammatic perspective view of, a fourth exemplary embodiment of a semiconductor component according to the invention;

FIG. 5 shows a diagrammatic perspective illustration of a fifth exemplary embodiment of a semiconductor component according to the invention;

FIG. 6 is a diagrammatic sectional, view of sixth exemplary embodiment of a semiconductor component according to the invention;

FIG. 7 is a diagrammatic sectional view off a seventh exemplary embodiment of a semiconductor-component according to the invention;

FIG. 8 is a diagrammatic sectional illustration of an eighth exemplary embodiment of a semiconductor component according to the invention; and

FIG. 9 is a diagrammatic sectional illustration of a semiconductor component according to the prior art.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the figures of the drawing in detail and first, particularly, to FIG. 1A thereof, the first exemplary embodiment has a window 1 with a first main surface 5, a second main surface 6, and a multilayer structure 2 applied to the first main surface 5.

The multilayer structure 2 comprises a plurality of semiconductor layers of the GaN/AlGaN system. The multilayer structure 2 contains an active layer 3, which generates radiation 18 during operation (illustrated by way of example using the rays 18 a, b, c).

The window 1 is produced from an SiC epitaxial substrate used for the epitaxial production of the multilayer structure 2 and has a trench-type recess 4 with a trapezoidal cross section, which has already been formed in the epitaxial substrate, preferably after the epitaxy.

Apart from this recess 4, the window 1 has a parallelepipedal enveloping basic form. As described in the introduction, in the case of such a device having a substrate whose refractive index is greater than the refractive index of the multilayer structure, the coupling-out of the radiation generated is greatly limited through the window sidewalls 8 on account of total reflection.

By virtue of the beveling of the aide surfaces 7 a, b of the trench-type recess 4, the angle of incidence is lowered for a part 18 b, c of the radiation reflected from the sidewall 8 of the window to such an extent that it is less than the angle of total reflection and the radiation can thus emerge from the window.

Radiation portions 18 a which, despite the inclination of the corresponding sidewall 7 a, are incident so shallowly that they are subjected to total reflection at the sidewall 7 a are reflected back and forth between the window sidewall 8 and the side surface of the recess 7 a, the angle of incidence decreasing after each reflection until a coupling-out is finally possible. This is elucidated for illustration purposes in the detail sectional view in FIG. 1B.

The angle α denotes the angle between the side surface of the recess 7 a and the sidewall of the window 8. A ray 18 a impinging on the recess side surface 7 a at an angle θ1 of incidence (θ1c, where θc is the angle of total reflection) is reflected back to the sidewall 8 under total reflection. The angle θ2 of incidence on the window sidewall 8 is reduced by the magnitude α compared with the angle θ1 of incidence during the prior reflection.
θ2−θ1−α

If, as illustrated, θ2 is greater than the angle θc of total reflection, the ray 18 a is reflected back to the side surface 7 a, where it impinges at the angle of incidence
θ3−θ2−α−θ1−2α

Thus, the angle of incidence is reduced by the magnitude α during each reflection until a coupling-out can take place.

The exemplary embodiment shown in FIG. 2 differs from the previous example in that, two recesses 4 a, b which cross one another at a right angle are formed in the window 1, each recess being embodied in the form of a trench with a trapezoidal cross section. As a result, the total coupling-out surface and thus also the radiation efficiency are advantageously increased further.

The recess described are preferably produced after the epitaxial production of the multilayer structure 2 by sawing into the epitaxial substrate on the side remote from the multi layer structure using a saw blade with a shaping edge. In this case, the shaping edge has, in cross section (section transversely with respect to the sawing direction), the complementary form corresponding to the desired trench cross section.

The exemplary embodiment shown in FIG. 2 is correspondingly produced by means of two sawing cuts that cross one another. In this case, the sawing depth is less than the window thickness in order not to damage the multilayer structure 2. The exemplary embodiment illustrated in perspective in FIG. 3 a differs from the previously described exemplary embodiment in that a spatially isolated, peripherally delimited recess 4 in the form of a hemisphere is formed in the window. Such peripherally delimited recesses are preferably etched into the window 1, in contrast to trench-type recesses. FIG. 3 b shows a central section through the exemplary embodiment, said section being perpendicular to the multilayer sequence 2.

The production of recesses by etching is suitable in particular for forming a multiplicity of recesses in a window 1, as are illustrated for example in FIG. 4. With the use of a suitable mask technique based on known technologies, it is possible in this case for all the recesses to be produced, cost-effectively in a single production step. The components thus formed are distinguished by a high radiation efficiency and a particularly uniform distribution of radiation on the coupling-out surface.

In the exemplary embodiment illustrated in FIG. 4, the contact connection is effected by means of metalized contact strips 9 a, b which run between the recesses and respectively end in a wire connection region 11 a, b. As mating contact, a contact surface 10 is applied to that side of the multilayer structure 2 which is remote from the window 1. Said contact surface 10 may be formed for example as a reflective surface. Radiation portions impinging on the contact surface are thereby reflected back again in the direction of the coupling-out surface 6. A contact surface formed in whole-surface fashion is advantageous for introducing current into the multilayer structure as uniformly as possible.

FIG. 5 likewise shows an exemplary embodiment with a plurality of recesses 4 in a window 1, which, in contrast to the previous exemplary embodiment, are arranged as trenches parallel to one another. The form of the individual recesses corresponds to the exemplary embodiment in accordance with FIG. 1. Such a structure can easily be produced by multiple parallel sawing-in using a shaping edge saw blade. This shaping is suitable in particular for large-surface semiconductor components.

The contact connection of the component is once again effected by means of two metalized strips 9 a, b which are applied to the main surface 6 and the recesses 4 near the edge and respectively end in a wire connection region 11 a, b. The corresponding mating contact is formed as a rear-side contact layer 10 on the multilayer structure 2.

The window sidewalls are partly beveled in the exemplary embodiment illustrated in FIG. 6, in contrast to the exemplary embodiments described above. In this case, the window sidewalls have, on the part of the first window main surface 5, a first partial region 8 a orthogonal to the main surface 5. This first partial region 8 a undergoes transition, in the direction of the second main surface 6, to a second partial region 8 b arranged obliquely with respect to the main surfaces 5 and 6. Furthermore, as in the exemplary embodiment illustrated in FIG. 1, a recess 4 with inclined side surfaces 7 is formed in the window 1.

The radiation efficiency is advantageously increased further by this shaping since the beveled regions 8 b of the window sidewalls reduce the proportion of radiation subjected to total reflection in a similar manner to the inclined side surfaces 7 of the recess 4. In the first partial region 8 a of the window sidewalls, the window additionally has, a parallelepipedal basic form which, as described, facilitates the mounting of the semiconductor component and is advantageous in particular for automatic placement installations. It goes without saying that the parallelepipedal basic form can also be entirely dispensed with in order to achieve an even higher radiation efficiency.

FIG. 7 shows an exemplary embodiment of, an optical component containing a radiation-emitting semiconductor component according to the invention. The semiconductor component corresponds to the exemplary embodiment in accordance with FIG. 5 and is applied to a metallic heat sink 12, for example a copper block. The heat sink is electrically conductively connected to the contact layer 10 formed on the rear side on the multilayer structure 2 and serves both for heat dissipation and for contact connection. In this case, the semiconductor component may be soldered or adhesively bonded onto the heat sink 12 by means of an electrically conductive adhesive.

The semiconductor component is covered with a potting 13 on the radiation side. Said potting comprises a reaction resin, preferably an epoxy, acrylic or silicone resin, which, inter alia, serves to protect the semiconductor component from harmful ambient influences.

In addition, the potting may also serve as a carrier or matrix for a radiation conversion element. Thus, by way of example, by suspending a suitable dye into the potting compound, it is possible to produce a component which radiates polychromatic light, that is to say light of a mixed color, comprising the light of the semiconductor component and the light converted by the dye. With the use of a semiconductor component which emits in the blue spectral region and a dye which, upon excitation in said spectral region, emits light in the yellow-orange spectral region, a semiconductor-based white light source is created in this way.

FIG. 8 shows a further exemplary embodiment of an optical component. Here, two semiconductor components corresponding to the exemplary embodiment in accordance with FIG. 5 are applied to an angled heat sink 12. A potting has been dispensed with since the shaping of the window layer already increases the coupling-out compared with components according to the prior art. The risks associated with a potting for the component, such as, for example, the risk of a delamination of the potting from the semiconductor body or a possible ageing and yellowing of the potting, are also obviated as a result.

As an alternative, of course, it, is possible to cover the semiconductor component by means of a potting if the latter is desirable for example in order to protect the semiconductor body, in order to form an optical element such as a lens, for instance, in order to further increase the radiation efficiency or as a matrix for luminescent materials.

The shaping of the window layer shown and, in particular, the formation of recesses in the form of a plurality of parallel trenches have the effect that the radiation generated, is radiated in a directional manner. Taking account of this directional radiating characteristic it is possible to produce modules with a plurality of semiconductor components which have a more complex radiating characteristic. Such more complex radiating characteristics, generally require additional complicated optics. The latter and likewise a reflector can advantageously be dispensed with in the case of the invention, so that modules of this type can be arranged in a particularly space-saving manner.

The scope of protection of the invention is not limited to the examples given hereinabove. The invention is embodied in each novel characteristic and each combination of characteristics, which includes every combination of any features which are stated in the claim, even if this combination of features is not explicitly stated in the claims.

This application claims the priority benefit of German patent application DE 1001 11 501, which is herewith incorporated by reference.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US3343026Nov 27, 1963Sep 19, 1967H P AssociatesSemi-conductive radiation source
US5038356Dec 4, 1989Aug 6, 1991Trw Inc.Vertical-cavity surface-emitting diode laser
US5087674Oct 11, 1990Feb 11, 1992Exxon Research & EngineeringBy-product inhibition
US5087949Mar 5, 1991Feb 11, 1992Hewlett-Packard CompanyLight-emitting diode with diagonal faces
US5814532Apr 29, 1997Sep 29, 1998Rohm Co., Ltd.Method of manufacturing semiconductor laser
US5814839Feb 14, 1996Sep 29, 1998Sharp Kabushiki KaishaSemiconductor light-emitting device having a current adjusting layer and a uneven shape light emitting region, and method for producing same
US5821568Dec 18, 1996Oct 13, 1998Sony CorporationMultilayer element with nitride of aluminum, gallium or indium for light emitting diodes
US5834325May 28, 1997Nov 10, 1998Sumitomo Electric Industries, Ltd.Light emitting device, wafer for light emitting device, and method of preparing the same
US5862167May 27, 1997Jan 19, 1999Toyoda Gosei Co., Ltd.Light-emitting semiconductor device using gallium nitride compound
US5905275Jun 16, 1997May 18, 1999Kabushiki Kaisha ToshibaGallium nitride compound semiconductor light-emitting device
US5907151May 27, 1997May 25, 1999Siemens AktiengesellschaftSurface mountable optoelectronic transducer and method for its production
US5925898Jan 26, 1998Jul 20, 1999Siemens AktiengesellschaftOptoelectronic transducer and production methods
US6071795 *Jan 23, 1998Jun 6, 2000The Regents Of The University Of CaliforniaSeparation of thin films from transparent substrates by selective optical processing
US6080599Jun 2, 1998Jun 27, 2000Kabushiki Kaisha ToshibaSemiconductor optoelectric device and method of manufacturing the same
US6229160Jun 3, 1997May 8, 2001Lumileds Lighting, U.S., LlcLight extraction from a semiconductor light-emitting device via chip shaping
US6239033May 21, 1999May 29, 2001Sony CorporationMaking a device using nitride iii-v compound semiconductors on one major surface of a single-crystal substrate; thinning said single-crystal substrate by processing the other major surface
US6239088Mar 19, 1999May 29, 2001Color Access, Inc.Nonirritating cleansing composition
US6291839Sep 11, 1998Sep 18, 2001Lulileds Lighting, U.S. LlcLight emitting device having a finely-patterned reflective contact
US6432521 *May 24, 2000Aug 13, 2002Fuji Xerox Co., Ltd.Forming at low temperature
US6495862Dec 20, 1999Dec 17, 2002Kabushiki Kaisha ToshibaNitride semiconductor LED with embossed lead-out surface
US6541799Feb 19, 2002Apr 1, 2003Showa Denko K.K.High emission intensity pn-heterojunction structure type; reduced in the absorption of emission attributable to a single crystal substrate; group 3 borophosphide intermediate layer
US6562648Aug 23, 2000May 13, 2003Xerox CorporationStructure and method for separation and transfer of semiconductor thin films onto dissimilar substrate materials
US6593159Mar 21, 2000Jul 15, 2003Matsushita Electric Industrial Co., Ltd.Semiconductor substrate, semiconductor device and method of manufacturing the same
US6611002Feb 23, 2001Aug 26, 2003Nitronex CorporationSmaller; vertically conducting even when nonconducting layer is included
US6677173 *Mar 28, 2001Jan 13, 2004Pioneer CorporationMethod of manufacturing a nitride semiconductor laser with a plated auxiliary metal substrate
US6730939Feb 12, 2001May 4, 2004Osram Opto Semiconductors GmbhRadiation emitting semiconductor device
US7329694Aug 28, 2001Feb 12, 2008Johnson & Johnson Vision Care, Inc.Ocular lens
US20010042866Feb 5, 1999Nov 22, 2001Carrie Carter ComanInxalygazn optical emitters fabricated via substrate removal
US20020086454Sep 4, 2001Jul 4, 2002Evans Gary A.Integrated grating-outcoupled surface-emitting lasers
US20030116774Dec 4, 2002Jun 26, 2003Kensaku YamamotoNitride-based semiconductor light-emitting device and manufacturing method thereof
US20030116791May 23, 2001Jun 26, 2003Robert BaptistSemiconductor device with vertical electron injection and method for making same
US20030127654Feb 15, 2001Jul 10, 2003Dominik EisertSemiconductor component which emits radiation, and method for producing the same
DE2727508A1Jun 18, 1977Jan 4, 1979Siemens AgLichtemittierende diode mit hohem wirkungsgrad
DE4218806A1Jun 6, 1992Dec 9, 1993Telefunken MicroelectronMesa LED with n-doped semiconductor substrate - has depressions formed over surface of p-doped epitaxial layer, pref. in edge region and extending to mesa flank
DE4324325A1Jul 20, 1993Jan 27, 1994Balzers HochvakuumOptical component mfr. by reactive etching - of metal oxide dielectric, esp. tantalum or hafnium oxide
DE19807758A1Feb 24, 1998Dec 10, 1998Hewlett Packard CoLichtemittierendes Element mit verbesserter Lichtextraktion durch Chipformen und Verfahren zum Herstellen desselben
DE19927945A1Jun 18, 1999Mar 23, 2000Hewlett Packard CoSemiconductor light emitting device, comprises emission layer between n-type and p-type layers, which emits visible light, and n- and p-type contacts connected to respective layers
EP0405757A2May 31, 1990Jan 2, 1991Hewlett-Packard CompanyHigh efficiency light-emitting diode
EP0442002A1Feb 13, 1990Aug 21, 1991Siemens AktiengesellschaftRadiation producing semiconductor device
EP0611131A1Feb 8, 1994Aug 17, 1994Sharp Kabushiki KaishaA method for producing a light-emitting diode having a transparent substrate
EP0810674A2May 23, 1997Dec 3, 1997Sumitomo Electric Industries, Ltd.Light emitting device, wafer for light emitting device, and method of preparing the same
GB2271087A Title not available
JP2000196152A Title not available
JP2000340882A Title not available
JP2001007390A Title not available
JPH0992878A Title not available
JPH1056209A Title not available
JPH03227078A Title not available
JPH11354845A Title not available
JPH11509687A Title not available
JPS61110476A Title not available
WO2001061765A1Feb 15, 2001Aug 23, 2001Osram Opto Semiconductors GmbhSemiconductor component which emits radiation, and method for producing the same
WO2001093310A2May 23, 2001Dec 6, 2001Robert BaptistSemiconductor device with vertical electronic injection and method for making same
Non-Patent Citations
Reference
1English translation of the Reason for Rejection issued in the corresponding Japanese application on Jan. 30, 2009.
2J. Zhang et al.: "Precise microfabrication of wide band gap semiconductors (SiC and GaN) by VUV-UV multiwavelength laser ablation", Applied Surface Science, vol. 127-129, 1998, pp. 793-799.
3Japan Patent Office, "Final Reasons for Refusal (English translation)", mailed on Dec. 4, 2009 (9 pages).
4Sze, S. M., "Physics of Semiconductor Devices", A Wiley-Interscience Publication, John Wiley & Sons, p. 848 (1981).
5W. N. Carr: "Photometric Figures of Merit for Semiconductor Luminescent Sources Operating in Spontaneous Mode", Infrared Physics, 1966, vol. 6, pp. 1-19.
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US8283676 *May 18, 2010Oct 9, 2012Siphoton Inc.Manufacturing process for solid state lighting device on a conductive substrate
US8304794Oct 31, 2011Nov 6, 2012Siphoton Inc.Light emitting device
US8313963Apr 26, 2010Nov 20, 2012Siphoton Inc.Light emitting device
US8624292Jun 8, 2011Jan 7, 2014Siphoton Inc.Non-polar semiconductor light emission devices
US8674383Jan 21, 2010Mar 18, 2014Siphoton Inc.Solid state lighting device on a conductive substrate
US8722441 *Jun 6, 2012May 13, 2014Siphoton Inc.Manufacturing process for solid state lighting device on a conductive substrate
US20110177636 *May 18, 2010Jul 21, 2011Pan Shaoher XManufacturing process for solid state lighting device on a conductive substrate
US20120241809 *Jun 6, 2012Sep 27, 2012Siphoton Inc.Manufacturing process for solid state lighting device on a conductive substrate
Classifications
U.S. Classification257/98, 257/103, 257/E33.068, 438/46
International ClassificationH01L33/02, H01L33/20, H01L21/00, H01L33/00
Cooperative ClassificationH01L33/02, H01L33/0079, H01L33/20
European ClassificationH01L33/20, H01L33/00G3D
Legal Events
DateCodeEventDescription
Feb 5, 2013CCCertificate of correction
Feb 9, 2012ASAssignment
Owner name: OSRAM AG, GERMANY
Free format text: CHANGE OF NAME;ASSIGNOR:OSRAM GMBH;REEL/FRAME:027679/0404
Effective date: 20110719
Oct 12, 2007ASAssignment
Owner name: OSRAM GMBH, GERMANY
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:OSRAM OPTO SEMICONDUCTORS GMBH;REEL/FRAME:019952/0714
Effective date: 20050615
Owner name: OSRAM OPTO SEMICONDUCTORS GMBH, GERMANY
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:BAUR, JOHANNES;EISERT, DOMINIK;FEHRER, MICHAEL;AND OTHERS;REEL/FRAME:019952/0652
Effective date: 20030915